FLUX.2 Flex Text-to-Image API by Black Forest Labs
FLUX.2 Flex is a professional text-to-image generation model specialized for typography, fine detail preservation, and production workflows requiring precise customization. It provides adjustable inference steps (1–50) and guidance scale (1.5–10) for fine-grained control, delivering high-quality output up to 4MP.
FLUX.2 Flex — Text to Image
Developer: Black Forest Labs
Model ID: black-forest-labs/flux-2-flex/text-to-image
Release Date: February 23, 2026
Overview
FLUX.2 Flex is a professional text-to-image generation model specialized for typography, fine detail preservation, and production workflows requiring precise customization. Built on latent flow matching with a rectified flow transformer architecture, it provides adjustable inference steps (1–50) and a guidance scale (1.5–10) for fine-grained control over the diffusion process.
Compared to FLUX.2 Pro, FLUX.2 Flex offers greater parameter control — making it the preferred choice for workflows that require balancing speed against output quality, or for tasks where text rendering and hex-accurate color are critical. The latest version is up to 3× faster than previous FLUX.2 Flex releases while maintaining the same high output quality.
Key Capabilities
- Superior typography — Reliable text rendering for complex typography, infographics, memes, UI mockups, and marketing materials with legible fine text.
- Adjustable inference parameters — Fine-grained control through configurable steps (1–50) and guidance scale (1.5–10) to balance quality, speed, and prompt adherence.
- High-resolution output up to 4MP — Flexible aspect ratios with a fundamentally improved VAE achieving 63.5% better learnability (gFID) and 84.1% better reconstruction quality (LPIPS) versus prior architectures.
- HEX color accuracy — Precise color matching using hex color codes for brand-accurate asset creation.
- Prompt expansion — Optional automatic prompt enrichment to improve output quality from short or simple prompts.
Use Cases
- Typography and text-heavy design — Infographics, magazine spreads, UI mockups, price tags, labels, and promotional materials requiring accurate text rendering.
- Brand asset creation — Logos, signage, and branded content with hex-code color accuracy.
- E-commerce and product design — Product descriptions, marketing materials, and campaign imagery.
- UI/UX design — Wireframes, interface mockups, and design systems with legible text elements.
- Advertising and media — Static ads, intro screens, credits, and text overlays.
- Rapid prototyping — Use lower step counts (6–20) for fast visual exploration; increase steps (40–50) for final-quality deliverables.
Input Parameters
| Parameter | Type | Default | Range | Description |
|---|---|---|---|---|
prompt | string | — | — | Text description of the image to generate. Required. |
width | integer | 1024 | 256–2048 | Width of the generated image in pixels. |
height | integer | 1024 | 256–2048 | Height of the generated image in pixels. |
steps | integer | 50 | 1–50 | Number of diffusion inference steps. Lower values are faster; higher values produce maximum fidelity. |
guidance | number | 5 | 1.5–10 | Guidance scale controlling how strictly the model follows the prompt. Higher values increase prompt adherence. |
enable_prompt_expansion | boolean | true | — | When enabled, the model automatically expands short prompts to improve output quality. |
output_format | string | jpeg | jpeg, png | Output image format. |
safety_tolerance | integer | 2 | 0–5 | Moderation strictness level. 0 = most strict, 5 = least strict. |
seed | integer | -1 | — | Random seed for reproducibility. Use -1 for a random seed. |
Steps vs. Quality Trade-off
| Steps Range | Recommended Use |
|---|---|
| 6–20 | Rapid prototyping, fast iteration |
| 20–40 | Balanced quality for general use |
| 40–50 | Maximum fidelity for final deliverables |
Output
Returns a URL to the generated image. The model supports asynchronous generation: the response first contains a polling URL, which resolves to the final image once generation is complete.
Output formats: JPEG, PNG Maximum resolution: 4 megapixels (e.g., 2048×2048)
Note: FLUX.2 Flex exhibits higher latency compared to FLUX.2 Pro, reflecting its emphasis on quality and fine-grained customization over raw speed.
Pricing
Pricing is based on the resolution of the generated image, measured in megapixels (MP). 1 MP = 1,048,576 pixels (e.g., 1024×1024). Resolution is capped at 4 MP for billing purposes.
SKUs
| SKU | Description | Unit Price |
|---|---|---|
sku_mp | Per megapixel of the generated image (up to 4 MP) | $0.05 |
Formula
cost = min(4, ceil(width × height / 1,048,576)) × sku_mp
Examples
| Resolution | Megapixels (billed) | Cost |
|---|---|---|
| 1024×1024 | 1 MP | $0.050 |
| 1024×1536 | 2 MP | $0.100 |
| 1536×1536 | 3 MP (ceil) | $0.150 |
| 2048×2048 | 4 MP | $0.200 |
Megapixels are always rounded up (
ceil) and capped at 4 MP. A flat per-megapixel rate applies uniformly across all resolution tiers, with no differentiated first-megapixel pricing.
